incubator-nuttx/drivers/power/pm/pm_checkstate.c

85 lines
3.1 KiB
C

/****************************************************************************
* drivers/power/pm/pm_checkstate.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <nuttx/power/pm.h>
#include <nuttx/clock.h>
#include <nuttx/irq.h>
#include "pm.h"
#ifdef CONFIG_PM
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pm_checkstate
*
* Description:
* This function is called from the MCU-specific IDLE loop to monitor the
* the power management conditions. This function returns the
* "recommended" power management state based on the PM policy applied by
* the currently chosen governor. The IDLE loop must call pm_changestate()
* in order to make the state change, which will interact with all drivers
* registered with the PM system.
*
* These two steps are separated because the plaform-specific IDLE loop may
* have additional situational information that is not available to the
* the PM sub-system. For example, the IDLE loop may know that the
* battery charge level is very low and may force lower power states
* even if there is activity.
*
* NOTE: That these two steps are separated in time and, hence, the IDLE
* loop could be suspended for a long period of time between calling
* pm_checkstate() and pm_changestate(). The IDLE loop may need to make
* these calls atomic by either disabling interrupts until the state change
* is completed.
*
* Input Parameters:
* domain - the PM domain to check
*
* Returned Value:
* The recommended power management state.
*
****************************************************************************/
enum pm_state_e pm_checkstate(int domain)
{
DEBUGASSERT(domain >= 0 && domain < CONFIG_PM_NDOMAINS);
if (g_pmglobals.domain[domain].governor->checkstate)
{
return g_pmglobals.domain[domain].governor->checkstate(domain);
}
return PM_NORMAL;
}
#endif /* CONFIG_PM */